Jouanin Jean-Claude, Dussault Caroline, Tran Denis, Guézennec Charles-Yannick
Dept. of Integrative Physiology, IMASSA, BP 73, F-91223 Bretigny-sur-Orge Cedex, France.
Aviat Space Environ Med. 2005 Dec;76(12):1151-5.
Aerobatic flights subject pilots to accelerations and, therefore, to heavy physical workloads.
Our aim was to document changes in spontaneous baroreflex sensitivity and disturbances of sympathovagal balance after exposure to "push-pull" accelerations.
During 30-min flights, five aerobatic pilots performed five series of descending spirals: first, 30 s under negative (-3 Gz max), and then 30 s under positive (+4 Gz max) G loading, climbing between each series to regain altitude. A stand-test was performed before (T0), immediately postflight (PF), 1 h (PF1), and 2 h after (PF2) the flight. A Finapres apparatus recorded heart rate (HR) and BP during the stand-tests.
Resting HR was higher at PF than T0 in supine (11.2 +/- 5.3%, p < 0.01) and standing (11.0 +/- 4.9%; p < 0.05) positions. Sequence analysis of spontaneous baroflex sensitivity (BRS) and spectral analysis of HR variability showed that: a) supine spontaneous BRS did not differ between preflight and postflight, while parasympathetic modulation of HR variability tended to increase; and b) supine spontaneous BRS was higher at PF1 than PF (PF: 0.011 +/- 0.0014 ms x mmHg(-1), PF1: 0.015 +/- 0.0012 ms x mmHg(-1); p < 0.05) and parasympathetic modulation of HR variability (high frequency component) was higher at PF2 than PF (PF: 0.014 +/- 0.007, PF2: 0.039 +/- 0.009; p < 0.001).
These findings may reflect a change in the sympathovagal balance during the second hour of recovery from repeated push-pull maneuvers.
特技飞行使飞行员承受加速度，因此承受繁重的体力负荷。
我们的目的是记录暴露于“推拉”加速度后自发性压力反射敏感性的变化以及交感迷走神经平衡的紊乱情况。
在30分钟的飞行过程中，五名特技飞行员进行了五组下降螺旋动作：首先，在负向（最大 -3 Gz）负荷下飞行30秒，然后在正向（最大 +4 Gz）负荷下飞行30秒，每组之间爬升以恢复高度。在飞行前（T0）、飞行结束后即刻（PF）、飞行后1小时（PF1）和飞行后2小时（PF2）进行立位试验。在立位试验期间，使用Finapres仪器记录心率（HR）和血压（BP）。
仰卧位（11.2±5.3%，p<0.01）和站立位（11.0±4.9%；p<0.05）时，飞行结束后即刻的静息心率高于飞行前。自发性压力反射敏感性（BRS）的序列分析和心率变异性的频谱分析表明：a）仰卧位时，飞行前和飞行后的自发性BRS无差异，而心率变异性的副交感神经调节趋于增加；b）仰卧位时，PF1时的自发性BRS高于PF（PF：0.011±0.0014毫秒×毫米汞柱-1，PF1：0.015±0.0012毫秒×毫米汞柱-1；p<0.05），且PF2时心率变异性（高频成分）的副交感神经调节高于PF（PF：0.014±0.007，PF2：0.039±0.0(09；p<0.001）。
这些发现可能反映了在从重复的推拉动作恢复的第二个小时内交感迷走神经平衡的变化。
